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Support Center / Therapies & Operation / The Thermostatic Control Valve (Anti-Scald): Which Faucets Have It, Its Setting, and Water-Heater Advice

The Thermostatic Control Valve (Anti-Scald): Which Faucets Have It, Its Setting, and Water-Heater Advice

Updated September 2026

Whether your Ella's Bubbles walk-in tub has an anti-scald thermostatic control valve (TCV) depends on the faucet configuration you ordered. Tubs equipped with an Ella thermostatic faucet package include a deck-mounted Thermostatic Control Valve that blends hot and cold water to a set temperature before it leaves the faucet, factory-set at 100.4 degrees Fahrenheit. Tubs ordered with the dual-lever 5-piece fast-fill faucet do not have a thermostatic valve; you set the temperature by hand with the red (hot) and blue (cold) levers. If you are not sure which faucet you have, the quickest way to find out is to open a ticket at ellasbubbles.com/support with your model and serial number.

Which Faucets Include the TCV

Ella's Bubbles offers the deck-mounted TCV on most of its acrylic walk-in tub line, and Ella's own safety article names the Elite, Petite, Royal, Deluxe and Companion among the models it is offered on. The valve sits on the deck next to the faucet and has its own control handle and governor.

  • Thermostatic faucet package: includes the Ella TCV. Hot and cold are blended automatically to the temperature you set.
  • Dual-lever 5-piece fast-fill faucet: not thermostatic. Red handle is hot, blue handle is cold, and the middle lever is the diverter for the hand shower.
  • 2-piece fast-fill faucet: a single lever (left for hot, right for cold) with a diverter button under the spout; not thermostatic.
  • Non-Ella faucets: carry their own manufacturer's warranty and are outside this article.

Because the faucet is chosen at order time, two tubs of the same model can differ, so check your order confirmation or look for the separate temperature handle on the deck. The 2-piece versus 5-piece faucet article shows what each set looks like.

How the TCV Protects You

In a shower you can step aside if the water suddenly runs hot. In a walk-in tub you cannot exit until the tub drains, so a temperature spike is a real safety concern. The TCV regulates the temperature of the water before it exits the faucet. If the cold supply drops, the valve limits the hot flow; if the hot supply drops, the valve limits the cold flow. The result is a steady temperature with no scalding spike and no cold thermal shock.

The Factory Setting and How to Adjust It

The TCV arrives set to 100.4 degrees Fahrenheit (38 C) and can be adjusted to suit your preference. Ella's owner's manuals list 100.4 F as the temperature above which bathing water becomes dangerous, so the factory setting is the safe bathing ceiling. You can turn the setting down for comfort. Turning it up above 100.4 F is not recommended, and the manuals ask bathers with heart conditions, those taking medication, and anyone who is pregnant to consult a physician before bathing in warm water. Our warm-water bathing guidelines cover temperature and soak time in more detail.

The video above is Ella's official walkthrough of adjusting the TCV temperature setting on the deck-mounted valve. If you would like written, model-specific adjustment steps for your faucet, open a ticket and the support team will send the correct thermostatic valve manual for your unit.

This feature overview shows where the TCV fits into the whole tub. Along with the adjustable step-in height, the removable stainless door, the swivel tray, the gravity dual drain, the in-line heater, hydro massage, heated seat and chromatherapy, it explains that dual massage models can be ordered with a 5-piece faucet whose thermostatic control valve locks at a safe 100.4 F and can be raised deliberately with a push of the button on the dial, a 60 inch retractable shower hose, and handle extensions on the diverters.

Should I Turn Down My Water Heater?

Ella's Bubbles' published guidance is to leave your water heater at its normal storage temperature and let the TCV do the blending. Some plumbers recommend lowering the water heater to prevent scalding and save energy. Ella's safety article on the TCV takes a different view: water stored below about 140 degrees Fahrenheit allows Legionella bacteria to grow, so the advantage of the TCV is that you can keep the heater at a safe storage temperature and still get a consistent, comfortable temperature at the tub faucet without a hot spike. For heater capacity and tankless flow, see what size water heater you need.

Why the TCV Gives Only Hot or Only Cold

A TCV that delivers only hot, only cold, or will not reach the set temperature almost always has a fouled cartridge or intake screen. Calcium, iron, sediment and other heavy particles in the water build up on the cartridge and the small intake screen, and the cartridge sticks so the valve can no longer blend. This is why the installer's warranty activation checklist includes operating the TCV on both hot and cold settings. What to keep in mind:

  • The TCV must be protected with an inline filter or mesh in the water lines, and that filter must be cleaned periodically. See protecting the TCV in hard water.
  • Removal and cleaning of the TCV should only be performed by a licensed and insured contractor or plumber. The step-by-step cleaning is in TCV cartridge cleaning and replacement.
  • Ella's Bubbles offers a cartridge-cleaning service at its facility for a nominal fee covering labor and shipping.
  • Replacement TCV units are available through Ella's parts department, and a legacy Thermostatic Control Valve Regulator is listed for older tubs. The support team will confirm the correct part for your model and serial number; the replacing an older TCV article covers supply sizes and the hidden deck-plate screw.

Is the TCV Under Warranty?

Yes, with an important difference from the rest of the tub. The Ella walk-in bath warranty states that the lifetime limited parts warranty does not apply to the thermostatic control valve. The TCV carries a one-year limited warranty, and that one-year warranty does not cover cartridge malfunction caused by contaminated water with calcium, iron or other heavy particles that leave the cartridge stuck. In practice, a stuck cartridge from hard water is a maintenance item handled through cleaning or replacement rather than a warranty claim. The full text is summarized in warranty exceptions for the TCV and faucets.

If Your Configuration Has No TCV

If your faucet is the non-thermostatic dual-lever set, you can still add scald protection. A qualified contractor can install an external temperature-control valve into the hot water line and preset it to the maximum safe temperature. Keep in mind that an added valve may reduce water flow and extend the tub's fill time. Ella's Bubbles recommends having a qualified contractor perform this installation.

Common Questions

Does my tub have anti-scald temperature control?
Only if it was ordered with the thermostatic faucet package. The dual-lever 5-piece and the 2-piece fast-fill faucets are not thermostatic. Check your order confirmation or contact the team with your serial number.
What temperature is the TCV set to, and can I change it?
It ships set to 100.4 F (38 C) and is adjustable. Ella recommends keeping bathing water at or below 100.4 F; the button on the dial lets you raise the setting deliberately, and the video above shows the adjustment.
Should I turn down my water heater?
Ella's published guidance is to keep the heater at its normal storage temperature so bacteria cannot grow, and let the TCV blend the water at the tub.
Why does the TCV only give hot or only cold?
The cartridge or intake screen is fouled by mineral buildup. Have a licensed plumber clean or replace the cartridge, and make sure an inline filter is fitted.
The TCV handle is stuck and will not turn below a certain point. Is there a lubricant?
A stiff or stuck handle is the same symptom as a fouled cartridge, so a lubricant on the handle will not fix it. The cartridge and screens need to be cleaned or the cartridge replaced by a licensed plumber; the cleaning video shows a light coat of lithium grease on the gaskets during reassembly.
Can I get just the TCV, without the rest of the faucet?
Yes. The TCV and its cartridge are supplied as separate parts, and a legacy regulator is listed for older tubs. Send a photo of the valve and your serial number so the team confirms the right one.
Is the TCV under warranty?
It has a one-year limited warranty that excludes cartridge problems caused by contaminated or hard water. It is not part of the lifetime parts warranty.
How long is the hand shower hose on the thermostatic 5-piece set?
The overview video describes a 60 inch retractable hose, which is the same 5 foot length as the standard fast-fill sets. Replacement hoses are matched to your faucet set.
Can I add a TCV to a tub that was ordered without one?
A qualified contractor can add an external temperature-control valve to the hot line and preset it. Ask the team before choosing a valve so it suits your faucet's flow; an added valve can slow the fill.

For anything specific to your model, faucet or serial number, open a ticket at ellasbubbles.com/support or call (800) 480-6850 and the Ella's Bubbles support team will be glad to help.

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